Language Map

Language map

You can learn Shelly in layers. The shell layer handles commands and their I/O; the value layer handles data; the application layer supplies interfaces and modules. A script can use all three without changing languages.

Foundations

• Language basics: statements, comments, quoting, and grouping.
• Variables and scope: declarations, assignment, shadowing, caller scope, and captured bindings.
• Numbers and logic: numeric promotion, arithmetic, equality, ordering, truthiness, and short-circuit evaluation.
• Strings and paths: Unicode text, interpolation, slices, home-directory display, and file patterns.

Collections and decisions

• Arrays: element contracts, slices, copying, spread, and stack methods.
• Hash maps: typed keys and values, lookup, and pairs.
• Ranges and iteration: bounded and open ranges, snapshots, and the next_item protocol.
• Control flow: if, for, while, until, and loop transfers.
• Match and type guards: value/range cases and narrowing.

Program structure

• Functions and calls: argument positions, results, executable references, aliases, and versioned definitions.
• Closures and function types: live captures, callbacks, prototypes, and optional arguments.
• Methods and properties: live $self, getters, setters, dynamic member names, and receiver-dependent contracts.
• Structs, Enums, Named types and unions.
• Conversions: explicit conversion and source/target hooks.
• Reflection: runtime types and discoverable interfaces.

Shell execution and composition

• Pipelines and Pipeline formats.
• Pipeline splits: nested branches, required alignment guides, streaming fan-out, and portable tab settings.
• Commands and exit status.
• Redirection and Environment.
• Errors and cleanup.

Modules and libraries

• Modules, Module packages, and Conditional code.
• Standard library and Prelude.
• Bytes and I/O, Item streams, JSON.
• Networking, HTTP, HTTP servers, Framing and RPC.

Interactive tools

• Startup and library selection.
• REPL and history, Prompts and widgets.
• Terminal formatting, Line editing, VS Code integration, Vim integration.

Recipes combines topics into small programs. The syntax reference is a compact reminder once the concepts are familiar.

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Related: Home · Syntax reference